E30 M30 Swap with Megasquirt. Need startup advice, please...

[CharMick]

I've been working on an E30/M30 swap for a couple of years and have gotten to the point where everything is installed, wired and plumbed. Car is a summer-only driver that is really just meant to be a weekend cruiser. Car is as follows:
1991 E30 325i Cabrio Automatic
1991 E32 735 3.5l M30
E32 bell housing and torque converter mated to E30 4HP22 transmission
Z3 4.27 Torsen LSD
Z3M 3 core radiator
External transimission cooler
E32 cooling fan
A/C delete
GM IAT sensor
AFM delete
Power steering delete (volvo electric ps pump in a box...something for a later day)
Megasquirt 2 DIY with wasted spark no ICV circuit
14.7 Spartan wideband O2 sensor
Mustang 24lb/hr injectors
6 GM LS2 truck coils
NGK plugs

I have an MSQ that I got from DIYautotune but I can only get the car to start...barely...and idle at about 500rpm. If I touch the throttle it dies. Smells very rich. I am using a manual ball valve to temporarily regulate idle air into the manifold it is barely cracked open. Throttle plate has been opened to about 2% to allow it to idle.

At the moment I have no exhaust attached to the exhaust manifolds. It will have 2-inch downpipes merging to one 3-inch pipe into performance cat, Vibrant quiet resonator and Borla muffler. All these stainless parts are purchased but not installed.

Is it pointless to try to continue getting some sort of running condition without an exhaust and installed O2 sensor? I was hoping to be able to drive it into a car dolly to get it to the muffler shop. Engine bay and spark/ignition tables shown:




Any help/suggestions are welcome!

Thanks.

Chuck

[JehTehsus]

If you just need to move it a bit, I would imagine generating a ve table would be adequate

*edit and by that I mean just use the internal 'generate ve table' function with parameters that are guesstimated. Set your entire AFR table to 14.7.

[CharMick]

Thanks! Took a while to get back because I injured my leg right after your reply and will be on crutches for 6 weeks. I did make the changes and found that I needed to change from Alpha-N to Speed Density which made a big difference. All values in AFR table are now 14.7. I need to burn that to the ECU and test but it will be a few weeks before I can.

I have the VE table that was originally calculated based on my engine and injector properties. Screenshot attached. Is that as good of a 'guess' as I can make or should I tweak it some based on the constant-value AFR table? If I did tweak it, any advice you have (or a link to VE tuning) would be great!

Thanks.

Chuck

[JehTehsus]

I think as far as an initial table goes it is going to be 'good enough' for the car to run, although on my build the calculated tables were quite rich. It should run the car though - but you don't really want to cruise around for a while running that rich, if that is how it ends up in your case. A few minutes while you move the car won't destroy things. Do not waste time trying to tune anything until your build is close to done, and you definitely will not be able to tune anything without an exhaust manifold and wideband.

If you have to move it a few times you may need to change the oil if it has been running extremely rich the entire time.

[CharMick]

Thanks. Appreciate the insight. I will give it a shot in a few weeks when I can get back into the car.

[JehTehsus]

Once you have everything together getting a basic rough yet functional tune goes fast. You do definitely want the wideband working though. I have already redone my fuel maps a couple times while I was tracking down a faulty FPR... not a big deal to do. When you're ready feel free to ping me, happy to help.

[CharMick]

A long time since my last post. The car is running and drives. When i attempt to Autotune (Megasquirted) it the AFR fluctuates wildly once the engine speed goes over 1000 rpm. I suspected an exhaust leak that is messing with the wideband O2 sensor. So I hooked a shop-vac blower up to it to pressurize the exhaust, sprayed soapy water on all welded exhaust joints that my exhaust 'expert' (now out of business) made, he welded everything from the muffler to the exhaust manifold. No flexes, no flanges. Did not use exhaust bolts I provided. Exhaust is joined to the exhaust manifold using a 'flared' pipe and the original flange hardware. The soapy water bubbles like crazy around both manifold outlets, at the joint. I was thinking I could use something like a Remflex gasket or a copper collector gasket to try to seal the gaps but upon closer inspection I'm not sure that will be possible. I am attaching 4 pictures of the leaky joints...any advice the forum has will be greatly appreciated.

Thanks!

[e30m3s54turbo]

I would order correct bolts. It looks like it is not lining up on flanges. You also need to massage fire a little or redirect exhaust pipe away from fire wall.

[CharMick]

I'll start with new bolts. The rear exhaust is actually about an inch away from the firewall. The angle of the picture makes it look closer. Since I will be removing the bolts and re-torquing is there any point/value in (forgive me) putting a thin layer of copper-based RTV between the exhaust pipes and the exhaust manifold? There seem to be mixed reviews on doing this...some have success, some not. It looks like the gap should be small so i could see how RTV might be good at providing a good seal. I was also considering making a copper conical seal that would fit between the cast iron manifold flange and the exhaust pipe. Something on the order of 0.02 inches of dead soft copper sheet cut and formed to fit. Thanks.

[CharMick]

Well, after additional life drama I am back at trying to get this thing to run.

After getting correct bolts and re-tightening the exhaust flange those leaks appear to be gone. The car drives but will not rev and once RPM gets up around 2500 it will backfire through the exhaust.

Is that something that would be caused by excessive ignition advance? I have had an issue in being able to set the Trigger Angle. The engine is an M30B35 from a 1992 E32. Everything I have found on the net says the Trigger Angle is somewhere between 84 and 86 degrees. Setting to 84 and fixed timing of 12 degrees and the O|T mark is nowhere to be seen.

Setting to 66 degrees with timing fixed at 12 and a non-adjustable timing light shows the O|T is about 2 teeth after the timing mark on the timing chain cover. Somehow I feel that I can't have a unique engine with TDC being different from everyone else's.

I took a picture of the 60-2 balancer and the O|T (marked in fluorescent orange) is 11 teeth from the first tooth after the two skip teeth. Which would indicate 66 degrees. Ignition table is shown in the original post of this thread.

Wasted spark, LS logic coils,

What am I doing wrong? I appreciate any help anyone can provide.

Thanks.

[Panici]

Have you set up Base Timing as per the ECU manual?

[Digitalwave]

Don't worry about other people's trigger angle. Just get yours right per the timing light.

For the rest of the issues, I'd say there isn't really enough info. Check and see if you are getting sync loss at 2,500 RPM. Otherwise maybe post a log here. It does sound like you would be best served by hiring a tuner, though.